Mobile communications networks are in the process of offering increasingly sophisticated capabilities associated with the position sensing of a mobile device. New software applications, such as those related to navigation, personal productivity, collaborative communications, social networking, data acquisition, etc., may utilize the position of the mobile device to provide new features and services to consumers. Such position determination capabilities may be provided using digital cellular positioning techniques and/or Satellite Positioning Systems (SPS).
In conventional digital cellular networks, position capability can be provided by various time and/or phase measurement techniques. For example, in Code Division Multiple Access (CDMA) networks, such as Long Term Evolution (LTE), one position determination approach used is Advanced Forward Link Trilateration (AFLT). Using AFLT, a mobile device may compute its position from phase measurements of pilot signals transmitted from a plurality of base stations. Improvements to AFLT have been realized by utilizing hybrid position techniques, where the mobile device may employ an SPS receiver that can provide position information independent of the information derived from the signals transmitted by the base stations. Moreover, position accuracy can be improved by combining measurements derived from both SPS and AFLT systems using conventional techniques.
Furthermore, navigation devices often support popular SPS wireless technologies that may include, for example, the Global Positioning System (GPS) and/or a Global Navigation Satellite System (GNSS). Navigation devices supporting SPS may obtain navigation signals as wireless transmissions received from one or more transmitter equipped satellites that may be used to estimate geographic position and heading. Some navigation devices may additionally or alternatively obtain navigation signals as wireless transmissions received from terrestrial based transmitters to estimate geographic position and heading.
Certain mobile devices, such as smartphones, tablet computers, and in-vehicle “infotainment” devices, typically include applications for navigation, driving directions, and/or pathfinding. These applications may use SPS or other techniques to determine the mobile device's position. Driving directions and other routes may be determined by the mobile device or by a server device in communication with the mobile device. Directions are typically generated for the route having the shortest distance or travel time between two points.